Bid to bring Lonesome George out of his shell

Picture: WAYNE TAYLOROne of the giant tortoises of the Galapagos with a baby star tortoise at Melbourne Zoo.

A loveless giant tortoise named Lonesome George is at the centre of an international effort to save his species from extinction through DNA.

He is the only remaining giant tortoise from the Galapagos island of Pinta, 1500 kilometres off the coast of Ecuador in the Pacific Ocean. He was found in 1971, alone on the volcanic island, a confirmed bachelor.

Since then Lonesome George - who is 80 years old and weighs 88 kilograms - has lived in a captive breeding enclosure on Isabella island, 200 kilometres away, in the company of female giant tortoises. But so far, their charms have eluded him. According to Dr Gisella Caccone, from Yale University in the US, he has mounted several females but none of the encounters have had a happy ending.

Dr Caccone, a delegate at Melbourne's International Genetics Congress, is a senior research scientist at Yale's department of ecology and evolutionary biology. She is also the director of Ecosave, a Yale unit studying near-extinct animals.

Through the DNA of giant tortoise subspecies from the Galapagos archipelago, Lonesome George included, she hopes to solve the riddle of their peculiar, isolated evolution and then prevent their extinction. The main islands being studied are the largest - Santa Cruz and Isabella.

Dr Caccone works in conjunction with the Charles Darwin Foundation. Darwin based many of his evolutionary findings on fieldwork done in the Galapagos archipelago.

"Each island in the group has its own unique species with unique genetics," she said. "They all have unique evolutionary lineages. Through DNA analysis we are trying to find how best to maximise pairing for the best genetic diversity of each subspecies."

The DNA is collected through blood from the giant tortoise's front leg. Lonesome George is quite small compared to some. The largest can weigh up to 200 kilograms. Bone and skin samples from extinct species have also been studied.

From 15 subspecies of giant tortoises in the archipelago, only 11 remain. But genetic studies are helping them to breed. On the island of Espanola, there are now 600 giant tortoises where once there were only 12.

"The program is working because there are more animals on the islands now," Dr Caccone said. "They are having babies. But on the other hand if the environment on the islands changes, this population will not be strong."

Dr Caccone said the giant tortoises had lived on the islands for 2 million years. They were culled for food by sealers and whalers in the 19th century. Modern threats came from tourism proposals on some Galapagos islands, El Nino weather patterns and wild goats, which breed rapidly and eat all the food. To solve the goat problem, teams of New Zealand hunters have been hired to fly over the island in helicopters, herd the goats and shoot them. Lonesome George, meanwhile, is fed papaya daily. It has kept him alive but failed to boost his libido. "I have to say that I think Lonesome George will never find a mate," Dr Caccone said. "He has been lonely for a long time."